As part of the 2018 effort, more than 100 cleanups will be held in Orange and Los Angeles counties, with thousands expected to pitch in.

The primary focus remains on keeping plastics and other non-biodegradable trash out of the ocean and off the beach, but more than two dozen cleanups will also be held at the region’s inland parks, waterways and nature areas. The event is touted as the state’s largest volunteer cleanup effort.

The top items collected in California cleanups over the past three decades are cigarette butts, food wrappers, bottle caps, cup lids, bags and straws, according to data compiled by the California Coastal Commission. The commission and the Ocean Conservancy help coordinate the events, which are individually sponsored by a host of groups including Heal the Bay, Orange County Coastkeeper, Trails4All and the Surfrider Foundation.

Below is a sampling of events in the two counties. Details of most events statewide — as well as information on reservations, required for some cleanups — can be found at coastal.ca.gov or on the interactive map below, with locations showing the meeting place.

Participants are encourage to bring their own reusable bags or buckets, gloves, reusable water bottles and sunblock. Most events begin at 9 a.m. and last until noon.

Martin Wisckol covers coastal environment and development. Previously, he spent two decades as politics reporter and columnist for the Orange County Register. He’s also held reporting positions in Miami, Jacksonville, Detroit and his hometown of San Diego, with an emphasis on land use and urban planning. He is a lifelong surfer and has spent most of his life on the coast. His work has been honored by the Society of Professional Journalists, the National Headliner Awards, the California Newspaper Publishers Association, the Florida Press Club and the American Planning Association Florida Chapter.